Flutter onAuthStateChanged stream not updating child when registering or signing in - flutter

Question

I wrapped my app inside a StreamProvider.value, where the value is an onAuthStateChanged stream, and the child is the main MaterialApp. My main wrapper listens to this value using Provider.of. This works fine for signing out; once I sign out, the StreamProvider notifies my main wrapper, and the app is redirected to the welcome screen.
But when I try to create an account or sign in, it seems the StreamProvider is not being notified of the onAuthStateChanged stream. This is why it's so weird, if the stream wasn't working, then signing out should also not work. Also, when I hot restart, I do get redirected to the home screen. I've scattered the internet: no luck. Here's the appropriate code:
In main.dart
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return StreamProvider<FirebaseUser>.value(
value: AuthService().userStream,
child: MaterialApp(
home: Wrapper(),
theme: ThemeData.light().copyWith(
appBarTheme: AppBarTheme(color: Colors.lightBlue),
scaffoldBackgroundColor: Colors.white,
),
),
);
}
}
In wrapper.dart
class Wrapper extends StatelessWidget {
#override
Widget build(BuildContext context) {
print('Rebuilding');
final user = Provider.of<FirebaseUser>(context);
if (user == null) {
return Welcome();
} else {
return Home();
}
}
}
In auth_service.dart
class AuthService {
FirebaseAuth _auth = FirebaseAuth.instance;
Stream<FirebaseUser> get userStream {
return _auth.onAuthStateChanged;
}
Future registerWithEmailAndPassword(String email, String password) async {
try {
AuthResult result = await _auth.createUserWithEmailAndPassword(
email: email, password: password);
FirebaseUser user = result.user;
return user;
} catch (e) {
print(e.toString());
return null;
}
}
Future signInWithEmailAndPassword(String email, String password) async {
try {
AuthResult result = await _auth.signInWithEmailAndPassword(
email: email, password: password);
FirebaseUser user = result.user;
return user;
} catch (e) {
print(e.toString());
return null;
}
}
void signOut() {
try {
_auth.signOut();
} catch (e) {
print(e);
}
}
}
Also, inside my welcome.dart, I have this set up as a test:
onPressed: () {
FirebaseAuth.instance.onAuthStateChanged
.listen((event) {
print('$event from .listen');
});
}
And this does notify my everytime I sign in, out or register, this tells me that there is nothing wrong with onAuthStateChanged, or the way I set it up.
If you need any more information, let me know. I don't want to make the question any longer. Thank you for your help!